1. Field of Invention
The present invention relates to an image input/output system for use in multi-function peripheral apparatus, such as a peripheral apparatus incorporating a scanner device and a printer device.
2. Description of Related Art
Peripheral apparatus are available for inputting an image to a host apparatus, such as a personal computer, or for outputting an image displayed by the host apparatus. For example, image scanners are used to read an image of a photograph, a text document or the like, and output the corresponding image data. Printers are used to print character data or image data output by host apparatus.
Conventional peripheral apparatus, such as printers and scanners, are separately connected to a host apparatus. Separate cables are used to connect an input/output (I/O) port of the scanner to an I/O port provided for a scanner in the host apparatus, and an I/O port of the printer to a printer I/O port of the host apparatus.
However, recently commercialized multi-function peripheral apparatus are capable of being connected to a host apparatus through a single cable. The multi-function peripheral apparatus can perform the function of two or more peripheral apparatus, e.g., a scanner device and a printer device.
Such a multi-function peripheral apparatus allows a user to have both a scanner device and a printer device, even if the installation space is limited, and facilitates connection to a host apparatus, since only one connecting cable is required.
However, in a system incorporating such a multi-function peripheral apparatus, if an error, e.g., a paper jam, occurs in the printer device, data transmission from the host apparatus to the printer device is rejected. In such a case, the multi-function peripheral apparatus outputs a busy signal to the host apparatus to switch off communication between the host apparatus and the multi-function peripheral apparatus. As a result, communication between the scanner device and the host apparatus is also switched off.
That is, if an error occurs in the printer device of a multi-function peripheral apparatus, the scanner device also becomes unusable, even if it has no operational problem. This impedes the efficient use of the multi-function peripheral apparatus.
Likewise, in a multi-function peripheral apparatus incorporating a sheet-feed-type scanner device, if an error, e.g., a document sheet jam, occurs in the scanner device, a busy signal is output to the host apparatus to switch off communication between the host apparatus and the multi-function peripheral apparatus. Therefore, the printer device in the multi-function peripheral apparatus also becomes unusable even though the printer device has no operational problem.